Effect of drought stress and methanol on radiation Use Efficiency and photosynthetically active radiation , leaf area index and extinction coefficient of Soybean max (L 17)

In order to evaluate drought stress and methanol on Radiation Use Efficiency and PAR and K ofsoybean in field experiments with factorial experiment Base of a randomized complete blockdesign with three replication in field faculty of agricultural of Islamic Azad university Karaj, at٢٠١٢. First factor were sprayed aqueous solutions ٠(control),٧,١٤.٢١,٢٨ and ٣٥%(v/v) methanolby ٣ times during growth season of soybean with ١٢ days intervals on shoot of soybean . Secondfactor were drought stress condition in two levels ٤٠%, ٧٠% base of depletion available soilmoisture. In this study were measured grain yield, dry matter, optimum leaf area, Radiation UseEfficiency and Extinction Coefficient and crop growth rate. Analyses of variance results show thatsprayed methanol solution has been effective on Radiation Use Efficiency and there is a significantdifference between applying treatments in ٥% level of possibility. Mean comparing shows that,the most quantity of Radiation Use Efficiency was belonging to ٢١% methanol voluminal levelthat in comparing with control has an increase of ١٥%. As well as results show that after ٩٦ dayspassing of planting, a significant difference in accumulation Photosynthetically Active Radiation bysoybean bush was observed in different methanol treatments. Sprayed methanol solution anddrought stress do not have any effects on Extinction Coefficient, but in spite of this, ExtinctionCoefficient in comparing with other level shows a decrease in level of ٢١%. Interactive betweenevaluated factors were not significant .

Keywords:

drought stress , methanol , leaf area index , Radiation Use Efficiency and Extinction Coefficient , accumulated Photosynthetic Active Radiation